​$1.4 million for a bridge: Not to build but demolish it

01 Oct 2017

Here is a gift West Vancouver wishes it had never accepted from the province: Nelson Creek Bridge. The district will have to spend $1.4 million just to demolish the bridge. Renovating the existing bridge isn’t an option and if the council decides to demolish and replace the bridge with a new one, they are looking at a $2.2 million price tag, according to an asset management report presented to the West Vancouver council.

A large portion of the city’s infrastructure is nearing its end because many of the assets were built 50 or 70 years ago.

A large portion of the city’s infrastructure is nearing its end because many of the assets were built 50 or 70 years ago. Last year, the district officials were asked to map assets and assess how much of a service they were providing to the community. Coun. Craig Cameron compared the Nelson Creek Bridge to a disease. “This was an unfortunate gift. It’s like gifting a disease in the sense that we have cost but very little upside to this. The cost of dismantling this is astronomical,” he said.

The 60-year-old bridge was decommissioned by the province and given to West Vancouver in 1974. It serves as a critical pedestrian connection to Whyte Lake Park and the Trans Canada Trail and supports a water main which provides water to areas west of Westport Road. The bridge is in such a rotten state that chunks of concrete have been falling in the creek below. The district did chip away at the underside in 2016 but the process was difficult and costly and required crews to gain access to the underside by rope. In any case, it was a temporary solution to a problem that will keep getting worse. New delamination would manifest at any time and would have to be dealt with again, staff notes.

In 2016, the district’s engineering department commissioned a study to find out if the bridge should be replaced or if it was possible to renovate it. The study brought forward two options: Rehabilitate the bridge and extend its life for another 40 years or dismantle the whole structure and build a new bridge.

A look at the numbers show that even renovation isn’t really an option. It would cost $4.6 million to extend the life of the bridge and at least $2.13 million will have to be in the first two years. And rehabilitation won’t address seismic requirements of the bridge building code. Not having it seismically upgraded poses a great risk to the water supply in the area since the sole connecting water main is currently being supported by the bridge.

“Rehabilitation of the existing bridge to seismic standards would be cost prohibitive and may not even be feasible,” staff noted in their report.
Staff is recommending to deconstruct the current bridge and replace it with a new 2.5 metre wide, 50 metre long steel pedestrian bridge which would also carry the water main under the structure. The new bridge would be built to seismic standards and use new technology to ensure lower maintenance cost. It’s expected to last for 75 years.

There is only a small window period for the dismantling, however. It will take $1.4 million to dismantle the bridge if work starts in the next two years.

There is only a small window period for the dismantling, however. It will take $1.4 million to dismantle the bridge if work starts in the next two years. If the bridge continues to deteriorate, the entrance to the bridge won’t be able to support the crane equipment needed to dismantle the bridge. If the deterioration gets beyond this point, demolishing the bridge will be very difficult and much more expensive, staff notes in the report. Staff suggested to council that the bridge be replaced before 2019, and staff investigate if the Ministry of Transportation and Infrastructure would pitch in with this project.

District officials said it had been typical in the past to not pay attention to the existing infrastructure assets. The prevailing idea on district assets was to “build, design and neglect” but now the district is trying to change that, an official told the council.